Research in language development has begun to focus on infants' expressions of a finite set of semantic relations. The present research is designed to better understand the prelinguistic, conceptual bases of the relations of agent of action and recipient of action. Preverbal and early verbal infants will be shown filmed events in the habituation paradigm which are designed to uncover first, whether infants can abstract the concepts of agent and recipient across many actions, and second, whether either relation is more salient in the processing of these events. Affirmative results from these experiments would contribute significantly to our understanding of the nonlinguistic roots of language development. In addition, such results would bear--albeit indirectly--on the issue of whether infants are expressing such concepts in their early utterances.